A senior Food and Drug Administration official says the agency cannot approve generic versions of EpiPen if manufacturers do not submit them.

The FDA's Dr. Douglas Throckmorton told House lawmakers that his agency has given the drug industry suggestions for developing drug injectors like EpiPen.

Lawmakers have pressed the FDA in recent days on what can be done to create more competition for Mylan's EpiPen.

The agency has a backlog of generic drugs under review, including a version of EpiPen from competitor Teva Pharmaceuticals.

But the company said earlier this year that regulators had found problems with its application. Teva's drug and several others aren't expected to hit the market until 2017 or later.

The head of pharmaceutical company Mylan defended the cost for life-saving EpiPens, signaling the company has no plans to lower prices despite a public outcry and questions from skeptical lawmakers.

In testimony for Congress, CEO Heather Bresch said Wednesday she believes Mylan has struck a balance between price and access to the drug. The price of EpiPens has grown to $608 for a two-pack, an increase of more than 500 percent since 2007.

Bresch said the company does not want to go back to a time when awareness of allergic reactions was much lower and many schools did not stock the drug.

The House Oversight and Government Reform Committee questioned Bresch about the pricing.